This invention relates to an improved closure means for a truck van having a movable closure web with an opening therethrough that is selectively positionable to facilitate loading and unloading the truck. The web is movable about the perimeter of the van between an operative position allowing access into the interior of the van through the opening and a home or inoperative position wherein access through the opening is prevented. Such a closure means if disclosed in U.S. Pat. No. 5,044,689, issued Sep. 3, 1991.
A problem with the flexible closure web disclosed in that patent is that when the truck is in motion, particularly at an accelerated speed along the highway, the longitudinally extending sides of the web have a tendency to bow inwardly due to the passage of air thereacross. Thus, means for tensioning at least the bottom portion of the web are desirable when the web is in its inoperative position and the truck is moving.
Also, means are needed to help guide the upper portion of the web along its movement about the perimeter of the van. Further, it is preferable to provide a means for sealing the upper part of the web from dust and debris which might enter the van over the top of the web as the truck moves.